A regenerative thermal oxidizer is used to clean polluted waste gas from an industrial process. Conventional RTOs are disclosed, for example in U.S. Pat. Nos. 5,562,442 and 5,700,443, which are incorporated herein by reference.
An RTO is constructed to receive polluted waste gases from an industrial process, cleanse the gas, and permit cleansed gas to exit the RTO to the environment. The RTO includes a lower section having an inlet to receive incoming waste gas that is polluted or contaminated, and a centrally positioned rotary distributor in the lower section that is used in controlling gas flow via a segmented center section. The rotary distributor is substantially smaller than the lower section and is of a substantially smaller cross section.
When in operation, incoming polluted gas is directed to a middle section segment or segments. The polluted gas fills the segment(s) and then flows through a peripheral opening to a segmented upper section where it passes through a combustion chamber. At the combustion chamber the polluted gas is cleansed to form outgoing gas. From the combustion chamber, the cleansed gas flows through a heat exchanger and back to a center section segment(s). In the center section the cleansed gas flows to the rotary distributor where it is divided into outgoing and purge gases. The outgoing gas flows through the rotor to a manifold and then to an outlet. The purge gas meanwhile flows through a purge segment in the rotor to a center discharge pipe where it is directed to a conduit for exiting the RTO. The purge gas is then recycled with the incoming gas to the RTO.
The combustion chamber of the RTO operates on fuel oil or natural gas. Given the volatile price of fuel oil, natural gas is seen as the most economical way of operating the combustion chamber. Natural gas, however, is also subject to price fluctuation. It is for this reason that a system that would allow for a reduction in the amount of natural gas used in the combustion process would be an important improvement in the art.